There are two commonly associated male physiological events that have a similar etiology. Benign prostatic hyperplasia (BPH) and male pattern baldness are both related to the enzyme 5-α reductase. (Hirsutism in women is also related to this enzyme.) An excess in activity of 5-α reductase has been shown to be responsible for BPH and male pattern baldness, as well as hirsutism in women. 5-α Reductase catalyzes the conversion of testosterone to 5α dihydrotestosterone (5α DHT). 5α DHT is a physiological ligand for an intracellular androgen receptor. The intracellular receptor has a higher affinity for 5α DHT than testosterone. Once the ligand has interacted with its cognate receptor, the receptor-ligand complex enters the nucleus and regulates gene expression.
Benign prostatic hyperplasia is the most common non-neoplastic disease process in men directly associated with aging. Although BPH has traditionally been a term used to refer to non-malignant enlargement of the prostate gland resulting from hyperplasia of the prostate epithelium and subsequent urinary outflow obstruction, recent studies have suggested that prostatic enlargement and histologic hyperplasia are only one facet of a larger syndrome consisting of both irratative and obstructive lower urinary tract symptoms, diminished urinary flow rate, and bladder dysfunction. Histologic evidence of BPH has been demonstrated in men as young as forty years; however, microscopic nodular hyperplasia associated with irritative symptoms or outlet obstruction is more commonly seen in men aged fifty to seventy. The frequency of symptomatic BPH is variable yet increases between the fifth and eighth decade of life.
Androgenetic alopecia can occur in both males and females. In men, hair loss generally occurs in the frontal, vertex, and upper occipital regions of the scalp while sparing the posterior and lateral margins. The process may begin at any age after puberty, with temporal hair recession usually noted first. There is no actual loss of hair, but rather a conversion of thick thermal hairs to fine, unpigmented hairs. In women, the pattern of hair loss is generally more diffuse with thinning throughout the scalp. Women with elevated androgen levels, as occur in masculinizing disorders, have a balding pattern similar to that of men. Treatment generally focuses on blocking the 5-α-reductase, the enzyme responsible for converting testosterone to dihydrotestosterone.
Hirsutism is the presence of excess hair in women. This phenomenon is usually an androgen-dependent process. Twenty-five to 35% of young women have terminal hair over the lower abdomen, around the nipples, or over the upper lip. Most women gradually develop more androgen-dependent body hair with age. Nevertheless, normal patterns of female hair growth are unacceptable to many women. At the other extreme, severe hirsutism may rarely be the earliest signs of masculinizing diseases. More often, however, severe hirsutism reflects only increased androgen production in women with a non serious underlying disorder.
There are other diseases associated with 5-α-reductase activity such as acne and seborrhea. The key for treating all of these diseases is the modulation of 5-α-reductase activity.
Currently there is a need for an economically feasible treatment regime that is safe and relatively inexpensive to combat diseases associated with 5-α-reductase.